On 11/08/2019 14:59, Pawel Laszczak wrote:
> Hi,
>
>>
>> On 21/07/2019 21:32, Pawel Laszczak wrote:
>>> This patch introduce new Cadence USBSS DRD driver to Linux kernel.
>>>
>>> The Cadence USBSS DRD Controller is a highly configurable IP Core which
>>> can be instantiated as Dual-Role Device (DRD), Peripheral Only and
>>> Host Only (XHCI)configurations.
>>>
>>> The current driver has been validated with FPGA platform. We have
>>> support for PCIe bus, which is used on FPGA prototyping.
>>>
>>> The host side of USBSS-DRD controller is compliant with XHCI
>>> specification, so it works with standard XHCI Linux driver.
>>>
>>> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
>>> ---
>>> drivers/usb/Kconfig | 2 +
>>> drivers/usb/Makefile | 2 +
>>> drivers/usb/cdns3/Kconfig | 46 +
>>> drivers/usb/cdns3/Makefile | 17 +
>>> drivers/usb/cdns3/cdns3-pci-wrap.c | 203 +++
>>> drivers/usb/cdns3/core.c | 554 +++++++
>>> drivers/usb/cdns3/core.h | 109 ++
>>> drivers/usb/cdns3/debug.h | 171 ++
>>> drivers/usb/cdns3/debugfs.c | 87 ++
>>> drivers/usb/cdns3/drd.c | 390 +++++
>>> drivers/usb/cdns3/drd.h | 166 ++
>>> drivers/usb/cdns3/ep0.c | 914 +++++++++++
>>> drivers/usb/cdns3/gadget-export.h | 28 +
>>> drivers/usb/cdns3/gadget.c | 2338 ++++++++++++++++++++++++++++
>>> drivers/usb/cdns3/gadget.h | 1321 ++++++++++++++++
>>> drivers/usb/cdns3/host-export.h | 28 +
>>> drivers/usb/cdns3/host.c | 71 +
>>> drivers/usb/cdns3/trace.c | 11 +
>>> drivers/usb/cdns3/trace.h | 493 ++++++
>>> 19 files changed, 6951 insertions(+)
>>> create mode 100644 drivers/usb/cdns3/Kconfig
>>> create mode 100644 drivers/usb/cdns3/Makefile
>>> create mode 100644 drivers/usb/cdns3/cdns3-pci-wrap.c
>>> create mode 100644 drivers/usb/cdns3/core.c
>>> create mode 100644 drivers/usb/cdns3/core.h
>>> create mode 100644 drivers/usb/cdns3/debug.h
>>> create mode 100644 drivers/usb/cdns3/debugfs.c
>>> create mode 100644 drivers/usb/cdns3/drd.c
>>> create mode 100644 drivers/usb/cdns3/drd.h
>>> create mode 100644 drivers/usb/cdns3/ep0.c
>>> create mode 100644 drivers/usb/cdns3/gadget-export.h
>>> create mode 100644 drivers/usb/cdns3/gadget.c
>>> create mode 100644 drivers/usb/cdns3/gadget.h
>>> create mode 100644 drivers/usb/cdns3/host-export.h
>>> create mode 100644 drivers/usb/cdns3/host.c
>>> create mode 100644 drivers/usb/cdns3/trace.c
>>> create mode 100644 drivers/usb/cdns3/trace.h
>>>
<snip>
>>
>>> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
>>> new file mode 100644
>>> index 000000000000..291f08be56fe
>>> --- /dev/null
>>> +++ b/drivers/usb/cdns3/gadget.c
>>> @@ -0,0 +1,2338 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Cadence USBSS DRD Driver - gadget side.
>>> + *
>>> + * Copyright (C) 2018-2019 Cadence Design Systems.
>>> + * Copyright (C) 2017-2018 NXP
>>> + *
>>> + * Authors: Pawel Jez <pjez@xxxxxxxxxxx>,
>>> + * Pawel Laszczak <pawell@xxxxxxxxxxx>
>>> + * Peter Chen <peter.chen@xxxxxxx>
>>> + */
>>> +
>>
>> <snip>
>>
>>> +/**
>>> + * cdns3_device_irq_handler- interrupt handler for device part of controller
>>> + *
>>> + * @irq: irq number for cdns3 core device
>>> + * @data: structure of cdns3
>>> + *
>>> + * Returns IRQ_HANDLED or IRQ_NONE
>>> + */
>>> +static irqreturn_t cdns3_device_irq_handler(int irq, void *data)
>>> +{
>>> + struct cdns3_device *priv_dev;
>>> + struct cdns3 *cdns = data;
>>> + irqreturn_t ret = IRQ_NONE;
>>> + unsigned long flags;
>>> + u32 reg;
>>> +
>>> + priv_dev = cdns->gadget_dev;
>>> + spin_lock_irqsave(&priv_dev->lock, flags);
>>> +
>>> + /* check USB device interrupt */
>>> + reg = readl(&priv_dev->regs->usb_ists);
>>> +
>>> + if (reg) {
>>> + writel(reg, &priv_dev->regs->usb_ists);
>>
>> Do we need to mask device interrupts till thread handler has done processing
>> current set of events?
>
> Yes, we need do this to avoid raising the next the same interrupts.
> If we return back from hard irq handler without clearing reported interrupts,
> then system report them again. The solution for this is to use IRQF_ONESHOT
> flag during registering interrupt, but I can't use this flag
> because I have shared interrupt line with other component.
>
> In this version these (usb_ists) interrupts are handled in hard irq, but in next version
> will be moved to thread handler.
>
>>> + cdns3_check_usb_interrupt_proceed(priv_dev, reg);
>>> + ret = IRQ_HANDLED;
>>> + }
>>> +
>>> + /* check endpoint interrupt */
>>> + reg = readl(&priv_dev->regs->ep_ists);
>>> +
>>> + if (reg) {
>>> + priv_dev->shadow_ep_en |= reg;
>>> + reg = ~reg & readl(&priv_dev->regs->ep_ien);
>>> + /* mask deferred interrupt. */
>>> + writel(reg, &priv_dev->regs->ep_ien);
>>> + ret = IRQ_WAKE_THREAD;
>>> + }
>>> +
>>> + spin_unlock_irqrestore(&priv_dev->lock, flags);
>>> + return ret;
>>> +}
>>> +
>>
>> <snip>
>>
>>> +
>>> +static int cdns3_gadget_start(struct cdns3 *cdns)
>>> +{
>>> + struct cdns3_device *priv_dev;
>>> + u32 max_speed;
>>> + int ret;
>>> +
>>> + priv_dev = kzalloc(sizeof(*priv_dev), GFP_KERNEL);
>>> + if (!priv_dev)
>>> + return -ENOMEM;
>>> +
>>> + cdns->gadget_dev = priv_dev;
>>> + priv_dev->sysdev = cdns->dev;
>>> + priv_dev->dev = cdns->dev;
>>> + priv_dev->regs = cdns->dev_regs;
>>> +
>>> + device_property_read_u16(priv_dev->dev, "cdns,on-chip-buff-size",
>>> + &priv_dev->onchip_buffers);
>>> +
>>> + if (priv_dev->onchip_buffers <= 0) {
>>> + u32 reg = readl(&priv_dev->regs->usb_cap2);
>>> +
>>> + priv_dev->onchip_buffers = USB_CAP2_ACTUAL_MEM_SIZE(reg);
>>> + }
>>> +
>>> + if (!priv_dev->onchip_buffers)
>>> + priv_dev->onchip_buffers = 256;
>>> +
>>> + max_speed = usb_get_maximum_speed(cdns->dev);
>>> +
>>> + /* Check the maximum_speed parameter */
>>> + switch (max_speed) {
>>> + case USB_SPEED_FULL:
>>
>> In this case we need to limit controller max speed to full-speed as system
>> integrator would expect that. e.g. in DT node, maximum-speed = "full-speed";
>>
>> I suppose we need to set the force Full-speed bit here?
>>
>>> + case USB_SPEED_HIGH:
>>
>> Here we need to restrict device controller max-speed to high-speed.
>>
>
> Why system integrator would limit the speed of controller?
To save cost? For many use cases, high-speed is more then sufficient.
> For debugging purpose it's ok, but in production system it's better
> to use higher speed.
> Do we relay need such functionality ?
Mostly for testing purpose. I can just change the DT node's speed property
to the lower speed to limit the controller to that speed.
If we can achieve that with a few lines of code, why not support it?
>
>>> + case USB_SPEED_SUPER:
>>> + break;
>>> + default:
>>> + dev_err(cdns->dev, "invalid maximum_speed parameter %d\n",
>>> + max_speed);
>>> + /* fall through */
>>> + case USB_SPEED_UNKNOWN:
>>> + /* default to superspeed */
>>> + max_speed = USB_SPEED_SUPER;
>>> + break;
>>> + }
>>> +
>>> + /* fill gadget fields */
>>> + priv_dev->gadget.max_speed = max_speed;
>>> + priv_dev->gadget.speed = USB_SPEED_UNKNOWN;
>>> + priv_dev->gadget.ops = &cdns3_gadget_ops;
>>> + priv_dev->gadget.name = "usb-ss-gadget";
>>> + priv_dev->gadget.sg_supported = 1;
>>> +
>>> + spin_lock_init(&priv_dev->lock);
>>> + INIT_WORK(&priv_dev->pending_status_wq,
>>> + cdns3_pending_setup_status_handler);
>>> +
>>> + /* initialize endpoint container */
>>> + INIT_LIST_HEAD(&priv_dev->gadget.ep_list);
>>> + INIT_LIST_HEAD(&priv_dev->aligned_buf_list);
>>> +
>>> + ret = cdns3_init_eps(priv_dev);
>>> + if (ret) {
>>> + dev_err(priv_dev->dev, "Failed to create endpoints\n");
>>> + goto err1;
>>> + }
>>> +
>>> + /* allocate memory for setup packet buffer */
>>> + priv_dev->setup_buf = dma_alloc_coherent(priv_dev->sysdev, 8,
>>> + &priv_dev->setup_dma, GFP_DMA);
>>> + if (!priv_dev->setup_buf) {
>>> + ret = -ENOMEM;
>>> + goto err2;
>>> + }
>>> +
>>> + priv_dev->dev_ver = readl(&priv_dev->regs->usb_cap6);
>>> +
>>> + dev_dbg(priv_dev->dev, "Device Controller version: %08x\n",
>>> + readl(&priv_dev->regs->usb_cap6));
>>> + dev_dbg(priv_dev->dev, "USB Capabilities:: %08x\n",
>>> + readl(&priv_dev->regs->usb_cap1));
>>> + dev_dbg(priv_dev->dev, "On-Chip memory cnfiguration: %08x\n",
>>> + readl(&priv_dev->regs->usb_cap2));
>>> +
>>> + priv_dev->dev_ver = GET_DEV_BASE_VERSION(priv_dev->dev_ver);
>>> +
>>> + priv_dev->zlp_buf = kzalloc(CDNS3_EP_ZLP_BUF_SIZE, GFP_KERNEL);
>>> + if (!priv_dev->zlp_buf) {
>>> + ret = -ENOMEM;
>>> + goto err3;
>>> + }
>>> +
>>> + /* add USB gadget device */
>>> + ret = usb_add_gadget_udc(priv_dev->dev, &priv_dev->gadget);
>>> + if (ret < 0) {
>>> + dev_err(priv_dev->dev,
>>> + "Failed to register USB device controller\n");
>>> + goto err4;
>>> + }
>>> +
>>> + return 0;
>>> +err4:
>>> + kfree(priv_dev->zlp_buf);
>>> +err3:
>>> + dma_free_coherent(priv_dev->sysdev, 8, priv_dev->setup_buf,
>>> + priv_dev->setup_dma);
>>> +err2:
>>> + cdns3_free_all_eps(priv_dev);
>>> +err1:
>>> + cdns->gadget_dev = NULL;
>>> + return ret;
>>> +}
>>> +
>>
cheers,
-roger
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